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What is kava kava?


Kava kava (piper methysticum), a flowering shrub belonging to the black pepper family, is available as a powder, capsule, liquid extract, root, and in several "herbal drinks." Its active ingredients are thought to be chemicals called kavalactones.

Kava kava uses

Kava has been used for insomnia, nervousness, anxiety, and tension. Although it isn't certain, it may be that kavalactones work in the brain like drugs such as Xanax® and Valium® to relax the mind and body. Kava's effectiveness has not been proven by medical research or directly compared to prescription drug therapy.

Some sources recommend 180 to 210 mg of kava one hour before bedtime. Follow package labeling carefully because the amount of kavalactones and dosages can vary from product to product.

Potential side effects

Kava kava's side effects include mild stomach irritation and drowsiness. Kava should not be taken for more than one month without a doctor's supervision because it may cause skin rash, and discoloration or drying of the skin, hair, and nails. Other kava kava side effects may also cause liver problems, such as jaundice, acute hepatitis, and enlarged liver. On March 25, 2002, the U.S. Food and Drug Administration (FDA) issued a consumer advisory that supplements containing kava may have the side effect of increasing the risk of liver damage. The FDA has received reports of liver-related injuries associated with kava use. Although the risk appears to be low, the FDA recommends that consumers with a history of liver disease discuss using kava supplements with their doctor.

Potential liver problems from kava kava

Early symptoms of liver problems include nausea, vomiting, stomach pain, tiredness, loss of appetite, dark urine, and jaundice (yellowing of the skin and eyes). Contact your doctor if you have any of these symptoms while taking kava supplements. Large doses of kava can have side effects similar to alcohol, causing drowsiness, loss of coordination, visual disturbances, and slow reflexes. This may affect your ability to drive or operate machinery. People who are depressed or who take medication for depression, anxiety, or seizures should not take kava. It is also not recommended for women who are pregnant or nursing.

Interactions between kava kava and other therapies

Kava kava does indeed have some interactions with certain drugs and other therapies. Kava kava can increase the effects of alcohol and certain drugs, including barbiturates (such as phenobarbital), anticoagulants such as warfarin (Coumadin®), and benzodiazepines (such as Xanax® and Valium®). It may also interact with antidepressants (such as Prozac®, imipramine, or Zoloft®), St. John's wort and valerian. It may also interact with monoamine oxidase inhibitors such as phenelzine (Nardil®) and tranylcypromine (Parnate®).

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